Filter doesn't work on the System Notifications screen
Description
While checking OLMIS-6361, I noticed that filtering by the author and the "Only Displayed" option does not work on the System Notifications screen.
Reproduction steps:
Log into application as an administrator and go to Administration > System Notifications.
Create at least one message.
Log out and log in as admin, go to Administration > System Notifications and create also at least one message.
Go to Administration > System Notifications, click the "Filter".
Select author Admin User and click the "Update" button.
All created messages are still displayed.
Edit one of the messages so that it is not active and save the changes.
In filter select "Only Displayed" option and click the "Update" button.
All created messages are still displayed.
Expected results:
It should be possible to filter messages.
NOTE: I think the "Update" button should be changed to "Search", as in other filters.
